You can use the discriminant rule, which is :
b^2 -4ac
“exactly one solution” means that it is equal to zero
so:
b^2 -4(4)(9)=0
b^2 -4(36)=0
b^2 -144=0
b^2=144
square root both sides
b=12 or -12
hope this helps !
12.075
Explain:
Price after mark-up: 10*115% = 11.5
Price after sales tax: 11.5 * 105% = 12.075
The answer is D
Because there are two x’s
And 5 number 1’s
So 2x=5
well, 6.2% of 4,300 can't be over half. she has made a calculation error, and the real answer is (this is where the mistake was made) 4,300 * 0.062 (not 6.2, because percents are always divided by 100 to make them into a usable number), which is equal to $266.60.
